
CZAEM
 A singlelayer model for simulating steady flow in homogeneous aquifers using the Analytic Element Method (Freeware). 
GFLOW
 A Windows program based on the analytic element method of steady state flow in a single heterogeneous aquifer using the DupuitForchheimer assumption (Educational version is free) . 
GMS 
GMS supports both finitedifference and finiteelement groundwater models in 2D and 3D including MODFLOW 2000, MODPATH, MT3DMS/RT3D, SEAM3D, FEMWATER, PEST, UTEXAS, MODAEM and SEEP2D. 
PhreFlow
 A program that models three dimensional unconfined transient groundwater flow and transport using the superposition of analytic functions (Freeware) . 
SLAEM/MLAEM
 The AEM family of computer programs, SLAEM, MLAEM/2, and MLAEM, are based on the Analytic Element Method and intended for modeling regional groundwater flow in systems of confined, unconfined, and leaky aquifers. 
Visual AEM
 A graphical user interface for single and multilayer analytic element modeling of (mostly) steadystate groundwater flow and numerical/analytical modeling of verticallyaveraged contaminant transport (Freeware) . 

BIOPLUMEIII

Finite difference model for simulating the natural attenuation of organic contaminants in groundwater due to the processes of advection, dispersion, sorption, and biodegradation. Biotransformation processes are potentially important in the restoration of aquifers contaminated with organic pollutants. As a result, these processes require evaluation in remedial action planning studies associated with hydrocarbon contaminants. 
GMS
 A comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
BIOF&T
 BIOF&T models biodegradation, flow and transport in the saturated and unsaturated zones in two or three dimensions in heterogeneous, anisotropic porous media or fractured media. BIOF&T allows real world modeling not available in similar packages. 
Bioslurp
 BIOSLURP is an areal finiteelement model to simulate threephase (water, oil and gas) flow and multicomponent transport in ground water in the unsaturated zone gas phase. 
BioSVE
 BioSVE incorporates soil vapor extraction (SVE), vacuum enhanced recovery (bioventing) and biodegradation into one easytouse screening model. BioSVE is a userfriendly screeing tool which allows site evaluation with limited sampling events. 
Groundwater Vistas
 Groundwater Vistas (GV) is a sophisticated Windows graphical user interface for 3D groundwater flow & transport modeling . GV couples a powerful model design system with comprehensive graphical analysis tools. 
Hydrogeochem
 HYDROGEOCHEM is a coupled model of hydrologic transport and geochemical reaction in saturatedunsaturated media. It is designed to simulate transient and/or steadystate transport of Na, aqueous components and transient and/or steadystate mass balance of Ns adsorbent components and ionexchange sites. 
Hydrogeochem2
 HYDROGEOCHEM 2 is a modification of HYDROGEOCHEM which was designed to solve coupled hydrologic transport and geochemical equilibrium problems. The modification includes replacement of the EQMOD chemical equilibrium subroutines by a mixed chemical Kinetic and Equilibrium Model (KEMOD) to deal with species whose concentrations are controlled by either thermodynamics or kinetics. 
Processing MODFLOW Pro (PMWIN)
 Processing MODFLOW Pro (PMWIN) is a graphical interface for MODFLOW, MODPATH, PMPATH, MT3D, RT3D, MOC3D, PEST and UCODE 

AGU10
 A collection of screening level analytical flow and transport programs for homogeneous, isotropic flow fields, based on the American Geophysical Union's Water Resources Monograph 10. It consists of five simulation programs in FORTRAN and two pre/postprocessors in Microsoft BASIC. (Freeware) . 
CAPZONE
 CAPZONE is an analytical flow model that can be used to construct groundwater flow models of twodimensional flow systems characterized by isotropic and homogeneous confined, leakyconfined, or unconfined flow conditions. CAPZONE computes drawdowns at the intersections of a regularlyspaced rectangular grid produced by up to 100 wells using either the Theis equation or the HantushJacob equation. (Freeware) 
PAT
 PAT is an analytical model for the computation and graphical representation of pathlines and travel times of groundwater in an infinite or semiinfinite homogeneous and isotropic confined aquifer. The computed steadystate flow field can include arbitrary pumping and injection wells superimposed with a natural homogeneous regional flow which is consistent with the boundary chosen. (Freeware) 
TWODAN

TWODAN, twodimensional analytic flow modeling software from Fitts GeoSolutions, was just upgraded to a 32bit Windows application (Version 5.0). This adds a simple and intuitive interface to TWODAN's advanced analytic modeling capabilities. 
WHAEM

WhAEM 2000 is a public domain, groundwater flow model designed to facilitate capture zone delineation and protection area mapping in support of the State's Wellhead Protection Programs (WHPP) and Source Water Assessment Planning (SWAP) for public water supplies in the United States. Program operation and modeling practice is covered in a series of progressively more complex representations of the wellfield tapping a glacial outwash aquifer for the city of Vincennes, Indiana. 
WHPA

The program 'WHPA' is a modular, semianalytical groundwater flow model designed to assist State and local technical staff with Wellhead Protection Area (WHPA) delineation. The model, developed for U.S. EPA, consists of 4 independent computational modules that may be used to delineate capture zones. 
ASM

ASM (Aquifer Simulation Model) is a numerical model for twodimensional horizontal or vertical simulation of groundwater flow and solute transport problems. The flow equation is solved using a nodecentered finite difference method. 
FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
FLOWPATH II

FLOWPATH is a 2D finite difference, steadystate groundwater flow model for calculation of wellhead protection zones, hydraulic heads, groundwater velocities, time related pathlines, capture zones, water balances and steady state drawdown distributions. 
GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
GROUNDWATER VISTAS

Groundwater Vistas (GV) is a unique groundwater modeling environment for Microsoft Windows that couples a powerful model design system with comprehensive graphical analysis tools. GV, developed by the author of ModelCadTM, is a modelindependent graphical design system for MODFLOW and related models. 
MODPATH


PATH3D

PATH3D can be applied to help visualize threedimensional flow fields, to delineate contaminant capture zones or wellhead protection zones, and to evaluate the effectiveness of groundwater remedial scenarios under complex hydrogeological conditions. PATH3D is a valuable extension to a groundwater flow model, and is frequently a practical alternative to a contaminant transport model. 
SWIFT

SWIFT98 is a fully transient, threedimensional model which simulates the flow and transport of fluid, heat (energy), brine, and radionuclide chains in porous and fractured geologic media. 
Data Managers

GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
GROUNDWATER VISTAS

Groundwater Vistas (GV) is a unique groundwater modeling environment for Microsoft Windows that couples a powerful model design system with comprehensive graphical analysis tools. GV, developed by the author of ModelCadTM, is a modelindependent graphical design system for MODFLOW and related models. 

MODFLOW: EPA PROBLEM SET

This manual addresses the principles of groundwater flow modeling and the modeling options associated with MODFLOW and provides twenty problem sets that illustrate use of MODFLOW including principles, input/output, options, rules of thumb, and common modeling mistakes.

PAJARO VALLEY  MODFLOW DATA SET

Pajaro Valley is a simulation data set for use with the threedimensional finite difference groundwater flow model MODFLOW by McDonald and Harbaugh (USGS, 1988). The data set represents a threelayer mathematical model of the Pajaro Valley Aquifer System, California, developed by Mitten and Londquist (USGS, 1990).

RANDOM WALK (RW) PROBLEM SET

This problems set features the random walk technique for studying solute transport problems in groundwater. It includes an analytical version of the Random Walk model and 8 problem sets demonstrating how the random walk technique works.


FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
HYDRUS2D/3D 
A MS
Windows Program for Simulating Water Flow and Solute Transport in Two and
/ThreeDimensional Variably Saturated Media with fullcolor, highresolution
Graphics User Interface 
MODFLOW 
MODFLOW is often used for fractured flow simulations, even though only the HFB Package specifically addresses fractured flow simulation. 
NETFLO

NETFLO is a model to simulate steadystate threedimensional groundwater flow in a heterogeneous medium using an equivalent network of series and parallel flow members. Where the stratigraphy does not suggest a particular network configuration, a network may be specified along principal stream tubes specified with a more general threedimensional groundwater flow code. 
POLLUTE

The POLLUTEv7 software provides fast, accurate, and comprehensive contaminant migration analysis capabilities. This program implements a one and a half dimensional solution to the advectiondispersion equation. 
SWIFT

SWIFT98 is a fully transient, threedimensional model which simulates the flow and transport of fluid, heat (energy), brine, and radionuclide chains in porous and fractured geologic media. 
TRAFRAPWT

TRAFRAPWT (TRAnsport in FRActured Porous media with Water Table boundary conditions) is a twodimensional finite element code designed to simulate groundwater flow and solute transport in fractured or granular aquifers, and is capable of treating both (leaky)confined and water table systems. Fractured porous media are represented by either the discretefracture or dual porosity approaches, or a combination of both. 
VERTPAK1

VERTPAK1 is a package of eight analytical solutions covering fluid flow, rock deformation and solute transport in fractured and unfractured porous media.


COVAR

COVAR is a program for generating twodimensional fields of autocorrelated parameters which are normally or lognormally distributed (e.g., hydraulic conductivity). The program uses a technique based on (Choleski) matrix decomposition. The generated parameter field represents a major requirement in the stochastic analysis via MonteCarlo techniques.

GEOEAS

GEOEAS (Geostatistical Environmental Assessment Software) is a collection of interactive software tools for performing twodimensional geostatistical analyses of spatially distributed data. Programs are provided for data file management, data transformations, univariate statistics, variogram analysis, cross validation, kriging, contour mapping, post plots, and line/scatter graphs. (Freeware) .

GEOPACK

GEOPACK is a userfriendly geostatistical software system. It consists of a package of programs for conducting analyses of the spatial variability of one or more random functions. GEOPACK includes several statistical analysis options. Basic statistics which can be calculated include the mean, median, variance, standard deviation, skew, kurtosis, maximum value, and minimum value. Programs are also included for linear regression, polynomial regression, and the KolomogorovSmirov test for distribution, and for calculating various percentiles of a selected data set. (Freeware) .

GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
MAP
 The Monitoring Analysis Package MAP has been developed as a tool for the design of monitoring networks. MAP consists of the Plume Generation Model PLUME, the Monitoring Efficiency Model MEMO, and the Contamination Probability Model COPRO. 

FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
HOTWTR

The program 'HOTWTR' is a blockcentered finite difference model for simulating threedimensional steadystate groundwater flow and heat transport in an isotropic, heterogeneous confined aquifer system with uniform thermal properties and no change of state. The interblock transmissivities are calculated as the harmonic mean of the adjacent blocks.

HST3D

HST3D:A Computer Code for Simulation of Heat and Solute Transport in ThreeDimensional GroundWater Flow Systems simulates groundwater flow and associated heat and solute transport in three dimensions (Freeware) .

HYDRUS 1D

HYDRUS1D is a Microsoft Windowsbased modeling environment for analysis of water flow and solute transport in variably saturated porous media. An interactive graphicsbased user interface HYDRUS1D was developed in support of the HYDRUS computer model (Freeware) .

HYDRUS2D/3D 
A MS
Windows Program for Simulating Water Flow and Solute Transport in Two and
/ThreeDimensional Variably Saturated Media with fullcolor, highresolution
Graphics User Interface 
ICE1

ICE1 is a research model for the analysis of coupled flow of water, heat and solute in unsaturated, partially frozen soils, including heave effects. The model is based on solving simultaneously equations representing the suctionwater content relationship, the hydraulic conductivity function, equation of state for energy of the liquid phase, approximate time integral of Darcy's law, approximate time integral of the Fournier heat diffusion equation, and the mass balance of solutes.

SEAWAT

SEAWAT is a generic MODFLOW/MT3DMSbased computer program designed to simulate threedimensional variabledensity groundwater flow coupled with multispecies solute and heat transport. The program has been used for a wide variety of groundwater studies including those focused on brine migration in continental aquifers as well as those focused on saltwater intrusion in coastal aquifers.

SUTRA

SUTRA is a model for saturatedunsaturated, variabledensity groundwater flow with solute or energy transport (Freeware) . 

MINTEQA2

MINTEQA2 is a geochemical equilibrium speciation model for dilute aqueous systems. The model can be used to calculate the mass distribution between the dissolved, adsorbed, and multiple solid phases under a variety of conditions including a gas phase with constant partial pressure.

MINTEQAK

MINTEQAK is an extensive modification of the MINTEQA2 code to model the change in composition of aqueous flow as it traverses a wetland/reactor system. The code allows modeling of an anaerobic wetland/ reactor, an aerobic wetland, or an anaerobic wetland/ reactor in series with an aerobic wetland.

NETPATH

NETPATH is an interactive program for modeling net geochemical massbalance reactions between an initial and final water along a hydrologic flow path. Alternatively, NETPATH computes the mixing proportion of two initial waters and net geochemical reactions that can account for the observed composition of a final water (Freeware) .

PHREEQC

PHREEQC is a computer program for speciation, reactionpath, advective transport, and inverse geochemical calculations. Designed to perform a wide variety of aqueous geochemical calculations (Freeware) .

PHREEQE

PHREEQE is a geochemical reaction model which is based on an ion pairing aqueous model. PHREEQE can determine pH, redox potential, and mass transfer as a function of reaction progress, and also solution composition in equilibrium with multiple phases.

PHRQPITZ

PHRQPITZ is a computer program capable of making geochemical calculations in brines and other electrolyte solutions of high concentrations using the Pitzer virialcoefficient approach for activitycoefficient corrections.

WATEQ4F

WATEQ4F is a program for the calculation of chemical equilibrium in natural waters. It models the thermodynamic speciation of major and important minor inorganic ions and complex species in solution for a given water analysis and in situ measurements of temperature, pH, and redox potential.


HYDRUS 1D

HYDRUS1D is a Microsoft Windowsbased modeling environment for analysis of water flow and solute transport in variably saturated porous media. An interactive graphicsbased user interface HYDRUS1D was developed in support of the HYDRUS computer model (Freeware) .

STANMOD

STANMOD (STudio of ANalytical MODels) is a Windows based computer software package for evaluating solute transport in porous media using analytical solutions of the convectiondispersion solute transport equation (Freeware) .

MAP
 The Monitoring Analysis Package MAP has been developed as a tool for the design of monitoring networks. MAP consists of the Plume Generation Model PLUME, the Monitoring Efficiency Model MEMO, and the Contamination Probability Model COPRO. 
OPTP

OPTP is a simple, userinteractive DOS program for computing the optimal discharge of a well in terms of benefit (of water produced) versus pumping cost, using a singlevariable (i.e., discharge) constrained nonlinear programming algorithm.


NAPL

NAPL Simulator conducts a simulation of the contamination of soils and aquifers which results from the release of organic liquids commonly referred to as NonAqueous Phase Liquids (NAPLS)


CXTFIT
 Successful predictions of the fate and transport of solutes in the subsurface hinges on the availability of accurate transport parameters (Freeware) .

PUMPTEST
 The PUMPTEST program package is a menudriven set of independently run programs.

SLUGC
 The program 'SLUGC ' is a graphic program for determining hydraulic conductivity values based on the analysis of slug tests using the Cooper, Bredehoeft and Papadopulos et al. method. The program simulates traditional manual curve fitting with an onscreen rendition of the graphical method, displaying the normalized Cooper et al. curves and the normalized field timedraw down data and subsequently moving the field data set using cursor keys to obtain the best fit.

SLUGT2
 SLUGT2 is an updated version of program 'SLUGT' and computes hydraulic conductivity values based on the analysis of slugtest data.

TGUESS
 TGUESS is a computer program for estimating transmissivity from specific capacity data. It calculates aquifer transmissivity using the Jacob equation and uses a correction for partial penetration as given by Sternburg (1973).

THCVFIT
 THCVFIT is an interactive program to determine transmissivity and storage coefficient from pumping tests. The program is based on the nonsteady state Theis equation for radial flow using the Theis curve fitting method.

THEISFIT
 THEISFIT uses a least squares procedure to obtain the "best" values for storage coefficient and transmissivity from experimental aquifer test data for an isotropic homogeneous nonleaky confined aquifer. It is based on an inverse formulation of the Theis equation solved using a least squares procedure.

TIMELAG
 TIMELAG is a program to estimate hydraulic conductivity from singlewell test. The method involves instantaneous raising or lowering of the water level in a well and measuring the waterlevel recovery through time.

TSSLEAK
 TSSLEAK uses a leastsquares fitting technique to calculate the "best" value for storage coefficient, transmissivity, leakage coefficient, and aquitard permeability from experimental pump test data as proposed by Hantush and Jacob.

UNGW
 The UNGW software package consists of two parts: 1) data bases and utilities, and 2) mathematical models.

VARQ
 VARQ is a program to calculate aquifer parameters by automatically fitting pump test data and the Theis type curve.

WELL
 WELL is a computer program for analysis of tracer test data. It analyzes dispersion of a conservative solute introduced as a pulse in the recharge well of a twowell flow system using the general theory of longitudinal dispersion in nonuniform flow along streamlines.

WELLTEST
 The WELLTEST program package consists of four independently marketed proprietary and public domain programs for the analysis of pump tests and slug tests.

ASM

ASM (Aquifer Simulation Model) is a numerical model for twodimensional horizontal or vertical simulation of groundwater flow and solute transport problems. The flow equation is solved using a nodecentered finite difference method. 
FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
FTWORK
 The program 'FTWORK' is a blockcentered finite difference model for simulating one, two and threedimensional steadystate and transient flow and transient single species solute transport in saturated media under confined and unconfined conditions.

INVFD
 INVFD is a twodimensional, steadystate groundwater flow model, which can be used to estimate parameters by nonlinear regression. The model simulates (leaky) confined flow in a heterogeneous aquifer.

MODFLOWP
 The WELLTEST program package consists of four independently marketed proprietary and public domain programs for the analysis of pump tests and slug tests (Freeware) .

PEST2000
 PEST is a nonlinear parameter estimation package with a difference. The difference is that PEST can be used to estimate parameters for just about any existing computer model, whether or not a user has access to the model's source code.

STANMOD

STANMOD (STudio of ANalytical MODels) is a Windows based computer software package for evaluating solute transport in porous media using analytical solutions of the convectiondispersion solute transport equation (Freeware) .

FP
 FP is a computer program for determining retention function parameters from experimental data. It is a historic model based an early formulation of the general retention function, relating the saturation to the capillary pressure in distributed soils.

ONESTEP
 ONESTEP is a program for estimation of up to five unknown parameters in the van Genuchten soil hydraulic property model. The program require measurements of cumulative outflow with time during onestep outflow experiments.

RETC
 RETC is a computer program which may be used to analyze the soil water retention and hydraulic conductivity functions of unsaturated soils. These hydraulic properties are key parameters in any quantitative description of water flow into and through the unsaturated zone of soils.

SOHYP
 SOHYP is an analytical model for calculation of the unsaturated hydraulic conductivity function. The basis of SOHYP is a relatively simple equation for the soil moisture contentpressure head curve.

SOIL
 SOIL estimates soil hydraulic properties using a nonlinear leastsquare analysis. Major input to the code includes pairs of measured water content and suction. The user can choose from the methods of Brooks and Corey (1964), Brutsaert (1966), Vauclin et al. (1979), and van Genuchten (1981) to estimate the soilwater characteristic function and the unsaturated hydraulic conductivity.


CASE

A package of five analytical models of the onedimensional convectivedispersive transport equation with linear adsorption, zeroorder production, and firstorder decay.

FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
HST3D

HST3D:A Computer Code for Simulation of Heat and Solute Transport in ThreeDimensional GroundWater Flow Systems simulates groundwater flow and associated heat and solute transport in three dimensions (Freeware) .

MOCDENSE

MOCDENSE is a twodimensional, crosssectional model for the analysis of saltwater intrusion. It simulates conservative solute transport and dispersion of one or two constituents in a groundwater system with densitydependent flow (Freeware) .

SEAWAT

SEAWAT is a generic MODFLOW/MT3DMSbased computer program designed to simulate threedimensional variabledensity groundwater flow coupled with multispecies solute and heat transport. The program has been used for a wide variety of groundwater studies including those focused on brine migration in continental aquifers as well as those focused on saltwater intrusion in coastal aquifers.

SHARP

The program 'SHARP' is a quasithree dimensional finite difference model for simulating freshwater and saltwater flow, separated by a sharp interface in layered coastal aquifers. The model accommodates multiple aquifers, separated by confining layers. The uppermost aquifer can be confined, semiconfined or unconfined with areally distributed recharge. Temporal variations in recharge and pumping are accounted for by introducing multiple pumping periods. The boundary conditions which can be modeled include prescribed flux boundaries, constant freshwater/and or saltwater head boundaries, mixed type boundary conditions. Aquifer properties can be both heterogeneous and anisotropic. The model can be used for both areal and crosssectional studies.

SUTRA

SUTRA includes the SUTRA groundwater model and a number of utilities for pre and postprocessing for simulations in two or three spatial dimensions (2D or 3D) (Freeware) .

SWICHA

SWICHA is a threedimensional finite element code for analyzing seawater intrusion in coastal aquifers. The model simulates variable density fluid flow and solute transport processes in fullysaturated porous media. It can solve the flow and transport equations independently or concurrently in the same computer run.

SWIFT

SWIFT98 is a fully transient, threedimensional model which simulates the flow and transport of fluid, heat (energy), brine, and radionuclide chains in porous and fractured geologic media. 
TARGET

A simple, userinteractive DOS program for computing the optimal discharge of a well in terms of benefit (of water produced) versus pumping cost, using a singlevariable (i.e., discharge) constrained nonlinear programming algorithm.

Saturated Flow
(Analytical) 
AGU10
 A collection of screening level analytical flow and transport programs for homogeneous, isotropic flow fields, based on the American Geophysical Union's Water Resources Monograph 10. It consists of five simulation programs in FORTRAN and two pre/postprocessors in Microsoft BASIC. (Freeware) . 
CAPZONE
 CAPZONE is an analytical flow model that can be used to construct groundwater flow models of twodimensional flow systems characterized by isotropic and homogeneous confined, leakyconfined, or unconfined flow conditions. CAPZONE computes drawdowns at the intersections of a regularlyspaced rectangular grid produced by up to 100 wells using either the Theis equation or the HantushJacob equation. 
GWFLOW

The program 'GWFLOW' brings together seven frequently used analytical solutions for groundwater flow problems. It is a simple program for quick calculations.

THWELLS

THWELLS is an analytical model for calculating the drawdown or buildup of piezometric head due to the combined effect of up to up to 100 pumping and/or injection wells. The calculation of total drawdown is based on the Theis equation or HantushJacob equation for nonsteady state flow in an isotropic, homogeneous confined, leaky confined or unconfined aquifer of infinite extent.

UNGW
 The UNGW software package consists of two parts: 1) data bases and utilities, and 2) mathematical models.

VERTPAK1

A package of eight analytical solutions covering fluid flow, rock deformation and solute transport in fractured and unfractured porous media.

WALTON35

A series of 35 simple analytical and numerical models for flow, solute and heat transport and upconing of a freshsalt water interface in saturated groundwater systems.

WHPA

The program 'WHPA' is a modular, semianalytical groundwater flow model designed to assist State and local technical staff with Wellhead Protection Area (WHPA) delineation. The model, developed for U.S. EPA, consists of 4 independent computational modules that may be used to delineate capture zones. 
Saturated Flow
(Numerical) 
ASM

ASM (Aquifer Simulation Model) is a numerical model for twodimensional horizontal or vertical simulation of groundwater flow and solute transport problems. The flow equation is solved using a nodecentered finite difference method. 
EIS/Biorem3D

EIS/Biorem3D is a W95 automated environmental modeling platform that integrates data management (geographical, physical, and chemical), site characterization, grid design, simulation of flow, migration, visualization, and scriptable interactions of multiple chemical species of 12 interacting plumes of chemicals, nutrients, and daughter products in saturated 3D media.

FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
FLOWPATH II

FLOWPATH is a 2D finite difference, steadystate groundwater flow model for calculation of wellhead protection zones, hydraulic heads, groundwater velocities, time related pathlines, capture zones, water balances and steady state drawdown distributions. 
FTWORK
 The program 'FTWORK' is a blockcentered finite difference model for simulating one, two and threedimensional steadystate and transient flow and transient single species solute transport in saturated media under confined and unconfined conditions.

GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
GROUNDWATER VISTAS

Groundwater Vistas (GV) is a unique groundwater modeling environment for Microsoft Windows that couples a powerful model design system with comprehensive graphical analysis tools. GV, developed by the author of ModelCadTM, is a modelindependent graphical design system for MODFLOW and related models. 
HST2D/3D ENHANCED

HST2D/3D is a finite difference computer model for the simulation of heat and solute transport in saturated porous media. The model is based on the original HST3D model developed by the USGS (Kipp, 1986), and is revised and extended by Verbeek Consultants for IF Technology in the Netherlands. 
HST3D

HST3D:A Computer Code for Simulation of Heat and Solute Transport in ThreeDimensional GroundWater Flow Systems simulates groundwater flow and associated heat and solute transport in three dimensions (Freeware) .

HYDRUS2D/3D 
A MS
Windows Program for Simulating Water Flow and Solute Transport in Two and
/ThreeDimensional Variably Saturated Media with fullcolor, highresolution
Graphics User Interface 
INVFD
 INVFD is a twodimensional, steadystate groundwater flow model, which can be used to estimate parameters by nonlinear regression. The model simulates (leaky) confined flow in a heterogeneous aquifer.

JDB2D/3D
 JDB2D/3D consists of two fairly simple, easily modifiable computer programs for solving the twodimensional, singleaquifer (JDB2D) and quasithreedimensional, multiaquifer (JDB3D) formulation of the transient groundwater flow equation for confined and leakyconfined aquifer systems.

MicroFEM
 MicroFem is an integrated largecapacity finiteelement modeling system for steadystate and transient simulation of groundwater flow in multiple aquifer systems. The software supports iteractive mesh generation, input preparation, model computation, graphic postprocessing and plotting of results.

MODFE
 MODFE is a modular 2D finite element model for simulation of steadystate or transient areal, crosssectional, and axisymmetric groundwater flow. Geometric and hydrologic aquifer characteristics in two spatial dimensions are represented by triangular finite elements and linear basis functions; 1D finite elements and linear basis functions represent time (Freeware) .

MODFLOW96
 MODFLOW is a blockcentered finite difference code for steadystate and transient simulation of twodimensional, quasithreedimensional, and fully threedimensional saturated, constant density flow problems in combinations of confined and unconfined aquiferaquitard systems above an impermeable base (Freeware) .

MODFLOWP
 The WELLTEST program package consists of four independently marketed proprietary and public domain programs for the analysis of pump tests and slug tests (Freeware) .

MULAT
 MULAT is a program for the analysis of threedimensional steadystate groundwater flow, and the advective transport of particles, including linear adsorption and desorption. The model assumes flow in the aquifer to be mainly horizontal, with vertical flow from one aquifer to another through the resistance layers.

NETFLO

NETFLO is a model to simulate steadystate threedimensional groundwater flow in a heterogeneous medium using an equivalent network of series and parallel flow members. Where the stratigraphy does not suggest a particular network configuration, a network may be specified along principal stream tubes specified with a more general threedimensional groundwater flow code. 
PLASM

PLASM as distributed by the IGWMC is a programs package based on the Prickett Lonnquist Aquifer Simulation Program (PLASM) first published in 1971 by the Illinois State Water Survey. It consists of three finitedifference simulation programs and a preprocessor. 
PMWIN

PM is graphical interface for simulation of threedimensional flow and solute transport problems. It supports the preparation of input files and analysis of simulation results for a range of MODFLOWrelated programs including MODFLOW itself, the particle tracking programs MODPATH and PMPATH, the transport program MT3D, and the parameter estimation program PEST (Freeware) . 
RADFLOW

RADFLOW is a menudriven, userinteractive finite difference model for solving the horizontal radial timevarying flow equation in a confined, semiconfined or unconfined aquifer. The program calculates drawdowns resulting from a pumping well in the center of a circular homogeneous, isotropic aquifer subject to uniform areal recharge. 
SUTRA

SUTRA includes the SUTRA groundwater model and a number of utilities for pre and postprocessing for simulations in two or three spatial dimensions (2D or 3D) (Freeware) .

SWIFT98

SWIFT98 is a fully transient, threedimensional model which simulates the flow and transport of fluid, heat (energy), brine, and radionuclide chains in porous and fractured geologic media. 

TRAFRAPWT 
TRAFRAPWT (TRAnsport in FRActured Porous media with Water Table boundary conditions) is a twodimensional finite element code designed to simulate groundwater flow and solute transport in fractured or granular aquifers, and is capable of treating both (leaky)confined and water table systems.

UNGW
 The UNGW software package consists of two parts: 1) data bases and utilities, and 2) mathematical models.

VISUAL GROUNDWATER

Provides interactive visualization capabilities for manipulating, rotating, and animating multiple threedimensional data sets

WALTON35

A series of 35 simple analytical and numerical models for flow, solute and heat transport and upconing of a freshsalt water interface in saturated groundwater systems.

Saturated Transport (Analytical) 
3DADE 
3DADE is a Fortran computer program for evaluating a series of analytical solutions of the 3Dimensional AdvectionDispersion Equation. The analytical solutions pertain to threedimensional solute transport during steady unidirectional water flow in porous media with uniform transport and flow properties (Freeware) 
AGU10
 A collection of screening level analytical flow and transport programs for homogeneous, isotropic flow fields, based on the American Geophysical Union's Water Resources Monograph 10. It consists of five simulation programs in FORTRAN and two pre/postprocessors in Microsoft BASIC. (Freeware) . 
AT123D

AT123D is based on an analytical solution for transient one, two, or threedimensional transport of a dissolved chemical or radionuclide or heat in a homogeneous aquifer with uniform, stationary regional flow. The program assumes a stationary flow field parallel to the Xaxis and allows for retardation (based on reversible instantaneous linear equilibrium sorption isotherm) and firstorder decay.

CXTFIT
 Successful predictions of the fate and transport of solutes in the subsurface hinges on the availability of accurate transport parameters (Freeware) .

EPSVHS

EPAVHS is a screening level model to predict maximum concentration of a pollutant at a prescribed distance downstream from a continuous source (at the compliance point). The model is based on an analytical solution for the transport of a conservative constituent in a homogeneous, isotropic aquifer with onedimensional, horizontal, steadystate flow and dispersion perpendicular to the flow path.

HPS

HPS is an analytical model for simulating threedimensional contaminant transport from a Horizontal Plane Source in a uniform regional ground water flow field. The model incorporates advective and dispersive (scaledependent) transport, retardation, and firstorder decay.

MAP
 The Monitoring Analysis Package MAP has been developed as a tool for the design of monitoring networks. MAP consists of the Plume Generation Model PLUME, the Monitoring Efficiency Model MEMO, and the Contamination Probability Model COPRO. 
ONED

ONED is a package of five analytical models of the onedimensional convectivedispersive transport equation with linear adsorption, zeroorder production, and firstorder decay. The governing transport equations include terms accounting for convection, diffusion and dispersion.

PLUME

PLUME, also called PLUMEPH, is an analytical model for calculation of point concentration in a homogeneous aquifer resulting from a continuous, timevarying release of a single radioactive or nonradioactive component from a horizontal line source.

PLUME 2D

The program 'PLUME2D' is an analytical model based on closedform solutions of the nonconservative solute transport equation for instantaneous and continuous releases of a tracer in one or more source locations as presented by Wilson and Miller (1978), and corrected by Wilson and Miller (1979).

PRINCE

PRINCE is a software package which contains ten analytical solute transport and flow models, widely known as the Princeton Analytical Models. The three flow models simulate twodimensional groundwater flow in a confined homogeneous, isotropic aquifer of finite, semifinite and infinite lateral extent.

RWH

RWH is an analytical version of the widely used RANDOM WALK flow and solute transport model, specifically designed for screening and educational purposes. It simulates solute transport from one or more sources in a homogeneous, isotropic, confined aquifer of constant thickness and infinite extent.

RANDOM WALK

The RANDOM WALK technique is outlined for studying mass transport problems dictated by analytical formula driven groundwater flow distributions. This is simpler than developing a finitedifference or finiteelement flow model as input to a mass transport techniques.

SOLUTE

The program package "SOLUTE" is a set of five programs based on analytical solutions of the advectivedispersive transport equation for a nonconservative tracer solute.

USGSSOL

USGSSOL presents a series of analytical solutions of the partial differential equation describing the advectivedispersive transport of a nonconservative solute for a variety of boundary types and solute source configurations in one, two, and threedimensions.

VERTPAK1

A package of eight analytical solutions covering fluid flow, rock deformation and solute transport in fractured and unfractured porous media.

WALTON35

A series of 35 simple analytical and numerical models for flow, solute and heat transport and upconing of a freshsalt water interface in saturated groundwater systems.

Saturated Transport (Numerical) 
ASM

ASM (Aquifer Simulation Model) is a numerical model for twodimensional horizontal or vertical simulation of groundwater flow and solute transport problems. The flow equation is solved using a nodecentered finite difference method. 
BIOPLUMEIII

Finite difference model for simulating the natural attenuation of organic contaminants in groundwater due to the processes of advection, dispersion, sorption, and biodegradation. Biotransformation processes are potentially important in the restoration of aquifers contaminated with organic pollutants. As a result, these processes require evaluation in remedial action planning studies associated with hydrocarbon contaminants. 
FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
FLOWPATH II

FLOWPATH is a 2D finite difference, steadystate groundwater flow model for calculation of wellhead protection zones, hydraulic heads, groundwater velocities, time related pathlines, capture zones, water balances and steady state drawdown distributions. 
FTWORK
 The program 'FTWORK' is a blockcentered finite difference model for simulating one, two and threedimensional steadystate and transient flow and transient single species solute transport in saturated media under confined and unconfined conditions.

GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
Groundwater Vistas
 Groundwater Vistas (GV) is a sophisticated Windows graphical user interface for 3D groundwater flow & transport modeling . GV couples a powerful model design system with comprehensive graphical analysis tools. 
HST2D/3D ENHANCED

HST2D/3D is a finite difference computer model for the simulation of heat and solute transport in saturated porous media. The model is based on the original HST3D model developed by the USGS (Kipp, 1986), and is revised and extended by Verbeek Consultants for IF Technology in the Netherlands. 
HST3D

HST3D:A Computer Code for Simulation of Heat and Solute Transport in ThreeDimensional GroundWater Flow Systems simulates groundwater flow and associated heat and solute transport in three dimensions (Freeware) .

HYDRUS2D/3D 
A MS Windows Program for Simulating Water Flow and Solute Transport in Two and
/ThreeDimensional Variably Saturated Media with fullcolor, highresolution
Graphics User Interface 
MIGRATE

Using the MIGRATEv9 software, contaminant transport from multiple sources, either at the surface or buried, can be modeled quickly and accurately in twodimensions.

MOC

A twodimensional finite element code designed to simulate groundwater flow and solute transport in fractured or granular aquifers, and is capable of treating both (leaky)confined and water table systems (Freeware) .

MOC3D

MOC3D is a 3D flow and transport model. The method of characteristics transport model is integrated with modflow and considers advection, dispersion, mixing from other fluid sources, linear sorption, and radioactive decay. Includes manual, source, executable and example files (Freeware) .

MOCDENSE

MOCDENSE is a twodimensional, crosssectional model for the analysis of saltwater intrusion. It simulates conservative solute transport and dispersion of one or two constituents in a groundwater system with densitydependent flow (Freeware) .

MODFLOWT

MODFLOWT is a new version of MODFLOW that includes modules for simulating threedimensional transport. The new model, authored by Glenn Duffield of HydroSOLVE, solves equations for advectivedispersive transport with adsorption and firstorder decay using a fullyimplicit finitedifference technique developed for the public domain code FTWORK by GeoTrans, Inc (see elsewhere in this catalog).

MT3DMS

The modular threedimensional transport model referred to as MT3D was originally developed by Zheng (1990) at S. S. Papadopulos & Associates, Inc., and subsequently documented for the Robert S. Kerr Environmental Research Laboratory of the United States Environmental Protection Agency.

MULAT

MULAT is a program for the analysis of threedimensional steadystate groundwater flow, and the advective transport of particles, including linear adsorption and desorption. The model assumes flow in the aquifer to be mainly horizontal, with vertical flow from one aquifer to another through the resistance layers. 
PHREEQM2D

PHREEQM2D is a multicomponent mass transport model consisting of two coupled simulation programs: HST2D and PHREEQE. PHREEQE is a geochemical reaction model developed by the U.S. Geological Survey. PHREEQM2D includes dissolution/precipitation and ion exchange, and supports kinetic computations for one mineral. 
PMWIN

PM is graphical interface for simulation of threedimensional flow and solute transport problems. It supports the preparation of input files and analysis of simulation results for a range of MODFLOWrelated programs including MODFLOW itself, the particle tracking programs MODPATH and PMPATH, the transport program MT3D, and the parameter estimation program PEST (Freeware) . 
POLLUTE

The POLLUTEv7 software provides fast, accurate, and comprehensive contaminant migration analysis capabilities. This program implements a one and a half dimensional solution to the advectiondispersion equation. 
RAND3D

The RAND3D program is a threedimensional version of the random walk algorithm developed by Thomas Prickett at the Illinois State Water Survey as an efficient algorithm for solving ground water solute transport problems (Prickett, Naymik, and Lonnquist, 1981). 
SUTRA

SUTRA includes the SUTRA groundwater model and a number of utilities for pre and postprocessing for simulations in two or three spatial dimensions (2D or 3D) (Freeware) .

SWICHA

SWICHA is a threedimensional finite element code for analyzing seawater intrusion in coastal aquifers. The model simulates variable density fluid flow and solute transport processes in fullysaturated porous media. It can solve the flow and transport equations independently or concurrently in the same computer run.

SWIFT98

SWIFT98 is a fully transient, threedimensional model which simulates the flow and transport of fluid, heat (energy), brine, and radionuclide chains in porous and fractured geologic media. 
TRAFRAPWT

TRAFRAPWT (TRAnsport in FRActured Porous media with Water Table boundary conditions) is a twodimensional finite element code designed to simulate groundwater flow and solute transport in fractured or granular aquifers, and is capable of treating both (leaky)confined and water table systems. Fractured porous media are represented by either the discretefracture or dual porosity approaches, or a combination of both. 
VISUAL MODFLOW



INFIL

INFIL is a numerical simulation model for solving the problem of ponded transient infiltration into a deep, homogeneous soil. The program is based on a fourterm form of the Philip series solution (1957) of a onedimensional form of the Richards equation.

FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
HYDRUS2D/3D 
A MS Windows Program for Simulating Water Flow and Solute Transport in Two and
/ThreeDimensional Variably Saturated Media with fullcolor, highresolution
Graphics User Interface 
SWACROP
 SWACROP (Soil WAter and CROP production model) is a transient onedimensional finite difference model for simulation of the unsaturated zone. It incorporates the process of water uptake by roots. 
UNSAT1
 UNSAT1 is a research model based on a generalized Hermetian finite element formulation for simulation of onedimensional flow in the unsaturated zone. This historic research code may be used to simulate moisture movement nonhomogeneous soils with both abrupt layering and smoothly changing soil characteristics. 
Unsaturated Transport (Analytical) 
HELP

The Hydrologic Evaluation of Landfill Performance (HELP) model was developed to help hazardous waste landfill designers and regulators evaluate the hydrologic performance of proposed landfill designs. The model accepts weather, soil and design data and uses solution techniques that account for the effects of surface storage, snowmelt, runoff, infiltration, evapotranspiration, vegetative growth, soil moisture storage, lateral subsurface drainage, leachate recirculation, unsaturated vertical drainage, and leakage through soil, geomembrane or composite liners.

ICE1

ICE1 is a research model for the analysis of coupled flow of water, heat and solute in unsaturated, partially frozen soils, including heave effects. The model is based on solving simultaneously equations representing the suctionwater content relationship, the hydraulic conductivity function, equation of state for energy of the liquid phase, approximate time integral of Darcy's law, approximate time integral of the Fournier heat diffusion equation, and the mass balance of solutes.

PESTAN

The program PESTAN represents model for evaluating the onedimensional vertical transport of organic pollutants through homogeneous soil to groundwater. It calculates organic movement based on a linear isotherm (S=K*C), firstorder degradation, and longitudinal dispersion.

RETC
 RETC is a computer program which may be used to analyze the soil water retention and hydraulic conductivity functions of unsaturated soils. These hydraulic properties are key parameters in any quantitative description of water flow into and through the unsaturated zone of soils.

SUMMERS
 SUMMERS is a screening level interactive computer program for estimating soil cleanup levels. The model assumes that a percentage of rainfall at a polluted site will infiltrate and desorb contaminants from the soil based on equilibrium soilwater partitioning.

Unsaturated Transport (Numerical) 
CHEMFLO

CHEMFLO is a onedimensional screening level model for simulation of the movement of water and chemicals in unsaturated soils. Water movement is described using Richards equation. The equation describing the movement of chemicals includes advective and dispersive transport, firstorder decay in the liquid and solid phase, zeroorder production or decay, and linear equilibrium adsorption (using a retardation coefficient.

FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
HYD1D

HYD1D is a Galerkin linear finite element program for simulation of transient 1D water flow, singlespecies solute transport, and heat movement in variably saturated porous media. The program solves the Richard's equation for flow, and convectiondispersion equations for both solute and heat transport.

HYDRUS 1D

HYDRUS1D is a Microsoft Windowsbased modeling environment for analysis of water flow and solute transport in variably saturated porous media. An interactive graphicsbased user interface HYDRUS1D was developed in support of the HYDRUS computer model (Freeware) .

HYDRUS2D/3D 
A MS Windows Program for Simulating Water Flow and Solute Transport in Two and
/ThreeDimensional Variably Saturated Media with fullcolor, highresolution
Graphics User Interface 
MIGRATE

Using the MIGRATEv9 software, contaminant transport from multiple sources, either at the surface or buried, can be modeled quickly and accurately in twodimensions.

POLLUTE

The POLLUTEv7 software provides fast, accurate, and comprehensive contaminant migration analysis capabilities. This program implements a one and a half dimensional solution to the advectiondispersion equation. 
PRZM2

PRZM2 links two subordinate models in order to predict pesticide fate and transport through the crop root zone, and the unsaturated zone: PRZM and VADOFT. PRZM is a onedimensional finitedifference model which accounts for pesticide fate and transport in the crop root zone. 
SESOIL

SESOIL is a finitedifference soil compartment model designed for longterm hydrologic, sediment, and pollutant fate simulations. The model is designed to estimate pollutant concentrations in the soil following introduction via direct application at the surface and/or interaction with other media (i.e., deposition from air). 
SUMATRA1

SUMATRA1 is a onedimensional Hermitian finite element (HFE) model for simulation of simultaneous movement of water and a solute in a heterogeneous soil profile. The transport equation includes the effects of linear adsorption and zero and firstorder decay. 
SUTRA

SUTRA includes the SUTRA groundwater model and a number of utilities for pre and postprocessing for simulations in two or three spatial dimensions (2D or 3D) (Freeware) .

SWMS_2D

SWMS_2D is a computer program for simulating water and solute movement in twodimensional variably saturated media. The program numerically solves the Richards' equation for saturatedunsaturated water flow and the convectiondispersion equation for solute transport (Freeware) . 
VS2DI

The VS2DI package contains all the tools that a user needs to create, run, and view results for a simulation of flow and transport through variably saturated porous media (Freeware) .


FEFLOW

FEFLOW is a professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface. 
GMS

GMS is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, postprocessing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D & 3D geostatistics, and both finite element and finite difference models in 2D & 3D. Currently supported models include MODFLOW, MODPATH, MT3D, RT3D, FEMWATER, and SEEP2D. 
Groundwater Vistas
 Groundwater Vistas (GV) is a sophisticated Windows graphical user interface for 3D groundwater flow & transport modeling . GV couples a powerful model design system with comprehensive graphical analysis tools. 
HYDRUS2D/3D 
A MS Windows Program for Simulating Water Flow and Solute Transport in Two and
/ThreeDimensional Variably Saturated Media with fullcolor, highresolution
Graphics User Interface 
HYDRUS 1D

HYDRUS1D is a Microsoft Windowsbased modeling environment for analysis of water flow and solute transport in variably saturated porous media. An interactive graphicsbased user interface HYDRUS1D was developed in support of the HYDRUS computer model (Freeware) .


AQUACHEM

AquaChem manages water quality data, allowing the user to plot data, perform common statistical analyses, model water chemistry with PHREEQC, and create simple reports.

POCKET ESA

This program has been designed to minimize the amount of time required to generate a Phase I ESA report and to maximize the flexibility of the final report. The data for the Phase I ESA can be collected on a Pocket PC or on a laptop.

POCKET WINLOG

Pocket WinLoG allows for quick and easy data collection in the field. You can use the stylus pen to enter any data into your logs or you can download your WinLoG templates to your Pocket PC for data entry in the field. Pocket WinLoG can store an unlimited number of templates previously designed in the WinLoG desktop version and pocket templates are represented on the menu tree form, displaying the types of data that can be entered for the log.

TETRA

TETRA estimates velocity components in three space dimensions from hydraulic head data. Groups of four observation points are connected to form tetrahedrons, and a linear interpolation is used to calculate head gradients for each tetrahedron.

UNITS

UNITS is a "Metric to InchPound to Metric" conversion utility, which uses dropdown menus to select and process 12 categories and 75 different units of measure often used in groundwater hydrology.

ZONEBUDGET

ZONEBUDGET is a program that calculates subregional water budgets using results from the U.S. Geological Survey Modular ThreeDimensional FiniteDifference GroundWater Flow Model (MODFLOW) (McDonald and Harbaugh, 1988).


PRZM2

PRZM2 links two subordinate models in order to predict pesticide fate and transport through the crop root zone, and the unsaturated zone: PRZM and VADOFT. PRZM is a onedimensional finitedifference model which accounts for pesticide fate and transport in the crop root zone. 
Virus Transport 
CANVAS

CANVAS is a composite analyticalnumerical code for simulation of transport and fate of viruses in groundwater. The code provides transient transport taking into account advection and dispersion of viral particles in the unsaturated and saturated zones, adsorption, inactivation (dieoff), attachment and detachment kinetics and colloidal filtration.

VIRALT

VIRALT is a modular semianalytical and numerical code that simulates the transport and fate of viruses in groundwater.

VIRTUS

VIRTUS (Viral Flow and Transport in the Unsaturated Zone) is a predictive finite difference model for virus fate and transport in unsaturated soil. The model allows the virus inactivation rate to vary based on soil temperature.
